android: camera_device: Cache request metadata

The settings in an android capture request may be null, in which case
the settings from the most recently submitted capture request should be
used. Cache the request settings to achieve this.

Signed-off-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>

src/android/camera_device.cpp

@@ -1696,6 +1696,16 @@ int CameraDevice::processCaptureRequest(camera3_capture_request_t *camera3Reques
 	 */
 	Camera3RequestDescriptor *descriptor =
 		new Camera3RequestDescriptor(camera_.get(), camera3Request);
+	/*
+	 * \todo The Android request model is incremental, settings passed in
+	 * previous requests are to be effective until overridden explicitly in
+	 * a new request. Do we need to cache settings incrementally here, or is
+	 * it handled by the Android camera service ?
+	 */
+	if (camera3Request->settings)
+		lastSettings_ = camera3Request->settings;
+	else
+		descriptor->settings_ = lastSettings_;
 
 	LOG(HAL, Debug) << "Queueing Request to libcamera with "
 			<< descriptor->numBuffers_ << " HAL streams";

src/android/camera_device.h

@@ -134,6 +134,8 @@ private:
 	int orientation_;
 
 	unsigned int maxJpegBufferSize_;
+
+	CameraMetadata lastSettings_;
 };
 
 #endif /* __ANDROID_CAMERA_DEVICE_H__ */